1. Field of the Invention
The present invention relates to a Theophylline sustained release granule which maintains suitable blood level of Theophylline.
2. Description of the Prior Arts
Theophylline has been used for therapy and prevention of asthma as a bronchodilator. Recently, pharmacological, biopharmaceutical and clinical studies of Theophylline have been developed to find the fact of the optimum concentration of Theophylline in blood which give satisfactory medical effect and low probability of side-effect. Therefore, the advantageous effect of Theophylline has been further recognized.
The side-effects of Theophylline may cause nausea or headache in high probability and also may cause unquietness, convulsion and tachycardia. These side-effects are caused depending upon a concentration of Theophylline in blood.
The medication of Theophylline is continued for a long period so as to prevent fits in chronic asthma. Therefore, it is important to give a precise plane for medication so as to maintain the optimum concentration of Theophylline in blood.
It is optimum to consider the medication of Theophylline at a dose suitable for individual patient each four to six hours. It is not so easy to continue such frequent medications everyday.
In such case, a sustained release medical composition is remarkably advantageous so as to minimize times of medication and to prevent sudden increase of a concentration of Theophylline in blood.
The other important problem in a therapy by the medication of Theophylline is that speeds of metabolism and discharge of Theophylline are highly different for each patient. It has been reported that a biological half-life of Theophylline in blood differs in a range of 3 to 9.5 hours. Therefore, it is preferable to determine each optimum dose by a quantative measurement of a concentration of Theophylline in blood for each patient. In view of the characteristics of medication of Theophylline, it is suitable to select a form of a composition which can sustain the effect of Theophylline and can easily select a dose of Theophylline to give a desired dose especially a sustained release granule in a medication for chronic asthma.